Pages

Wednesday, April 28, 2010

What Spider?

The General Manager brought a spider to me this morning. His family had caught it the night before and were impressed by its size. It was sealed in a glass with considerable quantities of tape and elastic bands. Houdini would have had trouble escaping.

I quickly identified it as a Wolf Spider. I am not sure which of the many species of wolf spider found in New Zealand it is. If you know send me a message.

The wolf spiders are hunting spiders and stalk their prey by stealth and quick movement. They possess good eyesight and hunt mostly at night. They are unusual in that some species the females carry their eggs in a silk sack on their abdomen. They may even carry the young hatchlings with them until they can fend for themselves.

This particular individual has a body of about 12mm and the from tip to tip of its hairy legs was as much as 50mm.

These are not dangerous spiders. There are few dangerous spiders in New Zealand. The Whitetail Spider is reported to bite frequently and in some cases causes severe reaction and perhaps ulceration of the bite site. The native Katipo is a relative of the Australian Redback and can, like its Aussie cousin, give a nasty bite which can in some very rare cases be fatal. The Katipo is non-aggressive and rare. It is found only in sandy areas near the coast.

You've heard of tarantulas and their tarantella dance.Well other spiders do the fang dango.

it may be the case that it is accepted that the toxin of white tail spiders is unlikely to cause ulceration and necrosis. There is still the possibility that the ulceration reported by many people who claim to have been bitten by a white tail is caused by infection of the bite site.

I have previously worked on a bacteria known as Mycobacterium ulcerans. This bacterium causes ulceration and is very difficult to isolate and identify. For hospitals to diagnose this bacterium as the cause of ulceration is hampered further by the treatment of ulceration with anti-biotics. There are other organism that could also be the cause of these reported ulcers.